Merge github.com:sos22/SLI

Manual fix for conflict in bdd.cpp.
Merge github.com:sos22/SLI

Conflicts:
	sli/bdd.cpp
Add some more timeout checks.
Avoid a stupid exponential blowup in realias analysis.
Avoid angering the OOM killed on very large probe CFGs.
Another missing special case in BDD quick simplify.
Merge github.com:sos22/SLI
Yet another special case in BDD quick simplifier.
It turns out that these bits of the interpreter weren't as redundant
as I thought they were.  Put them back.
Make it possible to tell whether enforce_crash really failed or just
suffered a timeout.
Try not to crash just because we showed that some path through the
crash plan is unreachable.
Whoops: remove some code which was only supposed to be there for
debugging.
Better normalisation for some BadPtr-related BDDs.
Make sure that phase 0 canonicalisation doesn't discard any MAIs
needed to interpret HB edges.
Lob in some more missing bytecode ops.
Add another timeout point to enforce_crash.
Using the inferred assumption to build the expression eval map turns
out to be too expensive.  Stop doing it.